2cy (argentatus), August
A 2cy argentatus, trapped and ringed as 2cy bird
orange C528J, today August 11 2002 in Tampere Finland (61.31N,23.43E). A bird with a pale iris, arm-span: 415 mm.
The complete moult is well underway with
most wing-coverts and the inner primaries moulted to second generation.
The outermost primaries P9-P10 are still juvenile. P1-P6 are fully
grown second generation flight-feathers. The primary moult score is 36. The outermost
secondary S1 has been replaced for a second generation feather. The next
three or four secondaries are missing and from about S5 inwards the
complete secondary-row is still juvenile.
The tail-feathers are moulted centrifugal, with the inner rectrices shed
first and two moult waves running outwards. In this bird, C528J, the outer
rectrices are still juvenile. The inner tail-feathers are renewed and show
a barred pattern. In many argentatus, the second generation
tail-feathers show only a narrow tail-band, which is sometimes rather
The upper tertials and most of the wing-coverts are replaced for second
generation feathers. The only wing-covert still to be replaced can be
found in the upper row of the lesser coverts, of which feathers are still missing in the carpal edge. All scapulars have been
replaced by second generation feathers, including the scapulars in the
By August, the warm brown tones of the first moulted
wing-coverts (inner greater coverts and median coverts) are faded to
plain white, leaving a contrasting barred pattern on the wing-coverts. On
average, 2cy argentatus is more contrastingly patterned than same
aged 2cy argenteus, especially regarding the pattern on the central
greater coverts. However, some argentatus (like this individual) are distinct "washed
out" brown, showing the common vermiculated pattern of 2cy argenteus.
last moulted coverts are the central greater coverts and outer lesser coverts, replaced by
mid-August. From mid-August onwards, 2cy argentatus start the partial autumn
moult, starting again to drop the upper tertial and inner greater and
In the table below, the primary moult
scores of 2cy August argentatus in Finland can be read:
in August, Tampere landfill, Finland, August 10 2002, 10:00-12:00 h.
primaries: m = 9.3, SD = 0.69, n = 139.
new primaries: m = 6.9, SD = 0.47, n = 139.